I think this is right (VM1, VM2 same availability set = Yes, Probe1.htm on VM1 and VM2, LB1 with balance between them = Yes, If rule 1 deleted, LB1 will blance all requests between VM1 and VM2 on all ports = No) based on: 1) Basic SKU doesn't allow flexibility in Availability Sets https://docs.microsoft.com/en-us/azure/load-balancer/concepts-limitations#skus 2) Rule1 health probe looks for /Probe1.htm - if it is present on both VMs, LB1 will balance between them 3) https://docs.microsoft.com/en-gb/azure/load-balancer/load-balancer-custom-probe-overview - Basic SKU, Probe down behaviour = All probes down, all TCP flows expire.

This one may cause some confusion, but "Yes", "Yes", "No" are the correct answers.

1st answer is wrong. Basic SKU load balancer does not support Availability Zones.

Yes about option 3, If SKU is basic and probe is down the TCP will expire but SKU is standard then TCP flows continue

The answer to first question should be No. I was able to create a "basic" sku load balancer using 2 VMs that are not in any Availability sets. Maybe the basic sku does not allow VMs from two different Availability sets to be added but that does not mean that VMs have to be in the same Availability sets. They might have no Availability sets associated.

Explanation for the last answer (No is correct) : "If all probes for all instances in a backend pool fail, no new flows will be sent to the backend pool. Standard Load Balancer will permit established TCP flows to continue. Basic Load Balancer will terminate all existing TCP flows to the backend pool. Load Balancer is a pass through service (does not terminate TCP connections) and the flow is always between the client and the VM's guest OS and application. A pool with all probes down will cause a frontend to not respond to TCP connection open attempts (SYN) as there is no healthy backend endpoint to receive the flow and respond with an SYN-ACK." -> https://docs.microsoft.com/en-gb/azure/load-balancer/load-balancer-custom-probe-overview#tcp-connections

Exam Question 12/23/2020

I just added VMs that are not part of a scale set or availability set. It worked. Does question A mean that the virtual machines cannot be in different availability sets ?

Are all the answers correct? No one had answered this yet.

The basic loadbalancer can have only VMs from a VMSS or a single VM. But why are we equating availability set to Scale Set for the first question? VM1/VM2 are in same scale set and not same availability set.

i think first one is "no" because availability set will not show the number of VMs within it so these are single VMs

Yes, Yes, No

For the Basic LB: I just made test so you have two possibilities : 1 : Add one VM 2: Add More than one VM but those VMs should be in the same Availability Set

Basic vs Standard regarding availibility sets???: The Standard Tier scale up a service out across 3 zones in a single region for a 99.99 percent service level agreement or SLA. The Basic Tier is limited to non-availability zone deployments. https://dynalearntech.com/learning-the-difference-between-basic-and-standard-azure-load-balancers.html

I think a basic lb sku doesnt support availability sets